The whole is worth more than the sum of its parts...

At the heart of the new generation APD rebreathers lays the Vision electronics package.

By combining the reliable, performance benchmark, oxygen control of the Inspiration Classic with the latest manufacturing methods used in high volume dive computers and extending their features, the Vision electronics bring even easier diving, simple yet innovative and advanced warning systems and simple upgradeability to allow not just safe software updates but also Hardware developments as they occur - future proofing your investment.

Without doubt one of the great advantages of the Vision package is the clarity of its communication of information to the diver in terms of content, readability and understanding. The wrist mounted Primary Display LCD Screen is crystal-clear (adjustable contrast) with easy-read numbers, graphics and written text to make the message unequivocal.
 

In normal use the information displayed includes: the oxygen controller, C1 or C2 - controlling the ppO2, the Setpoint, the Scrubber status (if the Scrubber Monitor option is chosen), the Battery status of both batteries and which one is providing the power for the solenoid and wrist display, the ppO2 from all three oxygen cells in real time as measured by the Master controller (or the Slave’s ppO2 displays at the touch-of-a-button request).

On the surface the date and time are shown with atmospheric pressure. Underwater the dive time and depth are shown along with maximum depth.

See the manual for the full list, but typical text warnings (given in capital letters) include things like: “START ERROR!” (if the pre-dive sequence is not completed properly), “HIGH OXYGEN”, “LOW OXYGEN”, “SCRUBBER WARNING”, “CELL WARNING”, “LOW BATTERY”, “SLOW” (ascent speed warning) and so on. These are all reinforced by other indications such as the scrubber bar graphic, battery graphics, the cell reading figures (etc), the buzzer and the HUD.

If either the Nitrox or Trimix decompression options are purchased the display also shows No Stop Time, which reverts to Total Time to Surface (TTS) and ceiling depth once the diver requires decompression stops.

APD CCR's are the only rebreathers with two independent oxygen controllers (patented). The Vision inherits this unique feature from the Inspiration Classic displaying both controllers’ readings of all 3 cells on the wristset. The Slave readings are hidden but can be simply called up and displayed for comparison with the Master readings (which never leave the display). The readings are in real time, that is, they change instantaneously, as PO2 variations occur, so that you see exactly what is happening with your oxygen pressure and with each cells’ performance (enabling you to easily spot an errant cell).

The Slave is independently powered and has several important functions. It will:

	independently generate warnings when appropriate.
	automatically promote itself to Master, adding oxygen when necessary, if the Master fails to signal its active status.
	instantly add oxygen to the loop if the PO2 drops to 80% of setpoint.

Having invented and patented the two controller system you would expect us to favor it but when you consider it carefully– it is an essential requirement.

So, why have two controllers?

When the battery power fades gradually and normally, you can give the diver a warning. But what happens if the battery power fails instantly? It might fail due to a faulty cell in a battery, not common but it happens; it might fail due to dirty battery contacts, not common but it happens; it might fail due to a broken joint either in the cabling or on a circuit board, again not common but it happens. With dual controllers, should any of these unlikely events occur, the Slave simply takes command, issues the warnings and you can then proceed as you see fit. On other makes of rebreather you only have one oxygen control system or one warning system and so in the above scenarios - you get no warnings! Will you notice that the solenoid has stopped firing? You might, but then again you might not - your brain may have switched off that flashing blue HUD light or you may be otherwise distracted.

The bottom line is – there is NO SUBSTITUTE for having a 2nd oxygen controller system.

The Vision electronics package gives essential decompression information, based on the real-time PO2 in the breathing circuit and real-time depth, using the Bühlmann ZHL16A-1b algorithm with gradient factor conservatism.

Whether you want a simple dive timer, Nitrox or an advanced Trimix computer the Vision is the answer both now and in the future.

By purchasing personalized activation-key release codes from APD and uploading to the unit, the decompression option is easily changed to suit every diver. The APD Communicator enables easy upgrades in the future should new decompression algorithms or techniques be developed, without returning the product to the factory.

You can program every gas on the boat!

With 6 user-defined and memorized gas mixes, for use as either closed circuit diluents or open circuit gases, the decompression calculations are continuous through every CCR and open circuit bail out scenario. Program your standard gasses for the season or change them for every dive - even underwater if you need to.

Unlike other dive computers there are no out-of-the-blue shutdowns- the Vision, as a by-product of it's primary life support role, has intelligent dual power supplies and other safe-guards built in to prevent this. Also, there are no “lock-outs” should you violate a decompression ceiling. If you don’t descend within a reasonable period the display simply continues showing “EST”imated deco until the computer has de-saturated.

Conservatism to suit you

Depending on your age, physical fitness, dive fitness and diving environment you may choose a more conservative ascent profile. Nitrox divers, with air in the diluent tank, are given a simple choice of 5 settings which are simply pre-programmed Gradient Factors while Trimix divers may enter the Gradient Factors directly into the Vision to allow cross-matching with dive planning software.

The Vision’s subtle Head Up Display in one neat little package has in fact two head up displays, one for each oxygen controller – i.e. two pairs of LED's, green on the bottom, red on the top – just 4 lights in all. The brightness of the LED's can be changed at any time - for instance you might not want it quite so bright on a night dive, but in bright daylight you may want to turn it up to max.

Some manufacturers have taken HUD lights to an art form worthy of a funky discotheque! When you take your diving seriously the last thing you need is flashing lights in your face mask throughout the dive. The brain switches out the normal occurrence, so we leave flashing lights for the warnings. This way the HUD really grabs your attention when it needs to, giving you warnings BEFORE danger levels are reached. Reinforced by the buzzer, we hit two of your senses simultaneously which really grabs your attention so you can take action before problems become critical.

In normal dive operation - when PO2 is close to setpoint - you see just two solid green lights, one for each controller. It stays on these until it has got something important to tell you for example slow flashing red is “low oxygen”, fast flashing is “high oxygen”- simple. Unlike some makes you don’t need to count the flashes to know what the HUD is telling you.
 

The other great benefit of the HUD is your buddy diver can see at a glance what the status of your unit is – they can see the reflection of the HUD in your face mask.

Because the HUD is an important part of the Vision’s information system the HUD has to be completely reliable. This is why we went with very strong, very flexible polyethylene fibre-optic rods, four sheathed into one, to transmit the light to the face mask – nothing to go wrong, nothing to flood, nothing to get damaged by pressure – simple and very effective (patent applied for).
In the unlikely event that the handset has failed, the HUD's, driven directly from their own controller, are still independently providing information about the unit and will tell you enough about battery, cell and PO2 status to enable a closed circuit egress. In total the Vision offers THREE independent display systems to the diver! The Vision electronics also feature many other suppressible and non-suppressible warnings and fail-safe systems.

Rebreathers have been around since the early 1900s however, a good simple, reliable, scrubber duration warning system has proved elusive - until now.

The display shows you not only what is happening in the scrubber, reflecting the diving conditions, but also warns you before CO2 becomes an issue. Unlike a CO2 sensor which warns you when CO2 is coming through (which is too late when you are deep) the Vision’s Scrubber Monitor warns you in advance of CO2.

Depth, work rate and water temperature are the three major factors affecting a scrubber’s duration and the APD Scrubber Monitor considers all three factors simultaneously – even working for partially used Sofnolime.

How it works

Using an array of digital temperature sensors molded into the centre stem the temperature profile of the scrubber is monitored in real-time. As the CO2 laden exhaled breath passes through the scrubber the temperature of each section is compared with the other sensors and the bar-display on the wrist set is updated to show the hot sections of the scrubber and by this means the exothermic reaction of the Sofnolime is tracked through the bed.

By using a comparative method, rather than monitoring actual temperatures, the APD Scrubber Monitor performs reliably and consistently in cold as well as warm water, it copes with ascents and descents, and even works with part-used Sofnolime, giving warnings at appropriate times on the HUD's and buzzer.

By extensive testing at the APD Research Laboratory the warning levels were determined at two very simple levels – Surface immediately and Go open
 

Why use a Scrubber Monitor?

It is impossible to conduct tests for every dive profile: you can only imagine the number of variations with parameters such as temperature, work rate and depth changing continuously throughout any one dive. Multiply this by the number of dives you’ll appreciate the dilemma. For this reason, for testing CO2 scrubbers harsh conditions are chosen. For instance the dive time quoted by the manufacturer might be typically 3 hours in 20m at 4C and a breathing rate of 40 lpm and CO2 production of 1.6 lpm. However, many divers spend much of the dive not breathing quite that hard and don’t necessarily operate in 4C water. So, the diver could be sure he can get more dive time than the duration quoted by the manufacturer but just how long?

Pushing the scrubber time might be successful one day but not the next due to unconsidered variables. This is where the APD Scrubber Monitor really excels. The reaction zone in the scrubber is affected directly by the work rate, depth and water temperature and this is accurately shown in the wrist set’s bar graph display.

The LogViewer’s front screen shows the depth/time dive profile, real-time PO2 display, PO2 switches, scrubber probe temperatures, any cell errors or warnings and surface interval, decompression, ambient temperature, battery voltages, and gas toxicity (CNS, OTUs). You can even ‘Copy and Paste’ the data into a Spreadsheet to create your own personal graphs. It shows the PO2 from all 3 cells and depth, recorded every 10 seconds, throughout the dive.
 

You can zoom in – almost indefinitely, you can even see the display you saw during the dive including the Scrubber Monitor. To ensure you don’t miss anything, “events” such as Ascent warning, or Cell warning are logged when they occur and these are clearly visible as you scroll across the dive display. There is an excellent Logbook section where you can manually record personal dive details and where it records automatically all your underwater time on that rebreather, what your surface interval prior to that dive was, what decompression safety margins you used etc etc. There is also a useful Gas Management section where you can determine exactly how much gas you have consumed.

Program updates, decompression options (Nitrox, Trimix) release codes, language files and User Registration screen updates may be downloaded over the internet and uploaded to the Vision electronics via the same interface. Additionally, the real time clock can be synchronized to your PC time.

The new Vision rebreathers allow safe software upgrades by you in your own home. Verified files, received over the internet, may be uploaded directly to your rebreathers electronics at the simple click of a button. Four data integrity checks for every line of code and for every file ensure clean files are loaded to your rebreather.

All firmware is upgradeable - when updates become available a simple upload is all that is required to load in future decompression programmers or rebreather code.

Multi-lingual

Through the upload feature the wristset’s language can be changed – includes English, French, German, Italian, Spanish, Portuguese, Dutch, Czech, Danish ( more added continuously).

Deco Options

Deco options are easily changed to convert the unit from a Dive Timer to Nitrox, to Trimix decompression models.
Instructors

Un-activated Rebreathers may be shipped from the factory in a “software disabled” condition if required – only activated with a unit specific pass-key.

User Groups

For Military customers bespoke User Groups are available ensuring non-compatibility of wrist set code and LogViewer PC software with the “Sport” User Group and other Military Groups.